The general commanding four loyalist columns moving on Madrid during Spain’s civil war (1936-39) referred to his militant supporters within the capital as his “fifth column.”

Nazi Germany and the Soviet Union maintained fifth columns in the United States. These were groups of secret sympathizers, sleeper cells, or supporters of an enemy that engage in espionage or sabotage, or simply disinform about the attacker’s intentions.

But as soon anyone suggests the presence of an Islamist equivalent in Western democracies, watch out. Militant Muslim “moderates” go into their well-rehearsed tonitruant mode. Islamophobia and McCarthyism are among the milder epithets.

Following the Madrid train bombings March 11 and the arrest of eight young British-born Pakistanis before they could put half a ton of ammonium nitrate to work against Heathrow Airport or the London Underground, Prime Minister Tony Blair decided “the enemy within” had to be sharply circumscribed. He ordered an end to any further debate on a national ID card and made it mandatory.

The new Fifth Column syndrome indicates the enemy inside the gates has plenty of bedlamites rooting for him in other countries. In Pakistan, some 66 percent believe Osama bin Laden is a good guy. As for the world’s biggest proliferators of nukes to America’s enemies, he has close to a 100 percent approval rating.

Recent opinion surveys among Britain’s almost 2 million Muslims, mostly from South Asia, rang alarm bells in Whitehall and in the media. Eighty percent were against the invasion of Iraq, 13 percent said another September 11-style attack on America would be justified, and 50 percent said they would consider becoming a suicide bomber if forced to live like Palestinians. Some 200,000 openly sympathized with Osama bin Laden.

Muslim sentiments are not much different in Continental Europe. Increasingly, Europeans are older and affluent and find themselves surrounded by immigrants who have little respect for local traditions. In the Netherlands, Muslims are a majority among children under 14 in the country’s four largest cities. Rotterdam, a port city where half the people are of foreign origin, will soon unveil Europe’s largest mosque. In Brussels, the capital of the European Union, Muhammad has been the name most frequently given for newborn baby boys. Osama is a close second.

While authorities claim it is well-nigh impossible to fool immigration officers with forged passports, a British reporter flew to Poland with no introductions, asked a few questions, was told where to go and in two days picked up a new Polish passport on the black market — it cost his paper $1,500 — and returned through British immigration unchallenged. The reporter said all kinds of forged documents were on offer. Quetta, the capital of Baluchistan in Pakistan, is also known for its expertise in forgeries and counterfeit currency.

Spain formally accused 12 Moroccans of involvement in the March 11 train bombing that killed almost 200 and injured 1,800. Of the 20 arrested, 16 are still in custody, including six charged with mass murder. Five blew themselves up as security forces closed on their suburban hideout near Madrid. They have ties to Islamist cells all over Europe. In France, raids on eight locations yielded and arrested 13 Moroccan militants. Their common base was across the narrow Strait of Gibraltar in once elegant Tangier where unemployment is 30 percent.

Several of them came from a middle-class background and had been enticed into a secret life of violence against Christians and Jews and even Muslims who worked with them, not by al Qaeda, but by a still more extreme movement called Salafia Jihadia. Most of its cadres had been trained in Afghanistan in al Qaeda’s camps but operated autonomously.

Muhammad Al-Fizazi, a fiery spellbinder, now serving a 30-year sentence in Morocco for inciting violence, inspired their fanaticism. He urged his disciples to “assassinate the impious” and “to love death as much as the impious love life.”

A paper found in the rented apartment of one Moroccan terrorist said, “We must develop immigration into Western countries as the path to the glory of Islam and the destruction of the Godless pagans.”

The Fifth Column is alive and well in the U.S. Abdurahman Alamoudi, an American citizen who was the prime mover behind the American Muslim Council (AMC) and a number of other U.S.-based Islamist-sympathizing organizations, is the man who certified 75 Muslim chaplains for service in the U.S. Armed Forces. He is a self-described supporter of Hamas and Hezbollah and was arrested at Heathrow last summer as he flew in from Libya on his way back to Washington. He had a little contretemps at the airport, unable to give British customs a plausible explanation for the $340,000 he was carrying in cash.

Mr. Alamoudi, now in jail in Virginia awaiting trial for allegedly lying to immigration authorities, was the most prominent leader of the Muslim World League in America, a Wahhabi Saudi front, made up of some 40 groups run by a small circle of trusted and wealthy individuals.

Mr. Alamoudi was directly involved in 16 Islamist front organizations. The network is controlled through four different layers of front organizations connected to Muslim charities and businesses in Northern Virginia. The FBI has gathered enough evidence to put away several prominent figures. But diplomatic relations with Saudi Arabia — and Saudi influence on the price of oil — have limited expulsions to 16 Arab clerics with Saudi diplomatic passports who were proselytizing impressionable young minds with inflammatory cliches about Jews and Christians.

The Council on American-Islamic Relations (CAIR) stubbornly refuses to concede that there are several thousand American Muslims — out of 6 million — who applaud the events of September 11, 2001, and firmly believe the U.S. is the fount of all global evil. Some 400 are currently being monitored 24/7 by the FBI. Either they have been fingered by Islamist prisoners — interrogated in Guantanamo, Bagram air base near Kabul, a U.S. Navy brig, and prisons in European countries — or phone taps or e-mail intercepts have shown their verbal propensity for violence against the hated American enemy.

CAIR tells us the latest findings on “Islam in America” show the vast majority of Muslim Americans hold “moderate” views on issues of policy, politics and religion. No one ever doubted that. It’s not the problem. What does CAIR have to say about a New Jersey firm that offered investments to wealthy Muslims, including housing developments in suburban Maryland, raised millions of dollars for what law enforcement authorities describe as a “who’s who” of international terrorists and Islamist extremists?

CAIR is in deep denial about the violent face of Islam. It’s time to care, CAIR. Also time for a Muslim to take the global lead against Islamist terrorism. Where is the Muslim Martin Luther King or Martin Luther who will become the uncontested voice of Islam?

Arnaud de Borchgrave is editor at large of The Washington Times and of United Press International.